// SPDX-License-Identifier: GPL-2.0-only
/*
 *  (c) 2005-2016 Advanced Micro Devices, Inc.
 *
 *  Written by Jacob Shin - AMD, Inc.
 *  Maintained by: Borislav Petkov <bp@alien8.de>
 */
#include <linux/interrupt.h>
#include <linux/notifier.h>
#include <linux/kobject.h>
#include <linux/percpu.h>
#include <linux/errno.h>
#include <linux/sched.h>
#include <linux/sysfs.h>
#include <linux/slab.h>
#include <linux/init.h>
#include <linux/cpu.h>
#include <linux/smp.h>
#include <linux/string.h>

#include <asm/traps.h>
#include <asm/apic.h>
#include <asm/mce.h>
#include <asm/msr.h>
#include <asm/trace/irq_vectors.h>

#include "internal.h"

#define NR_BLOCKS         5
#define THRESHOLD_MAX     0xFFF
#define INT_TYPE_APIC     0x00020000
#define MASK_VALID_HI     0x80000000
#define MASK_CNTP_HI      0x40000000
#define MASK_LOCKED_HI    0x20000000
#define MASK_LVTOFF_HI    0x00F00000
#define MASK_COUNT_EN_HI  0x00080000
#define MASK_INT_TYPE_HI  0x00060000
#define MASK_OVERFLOW_HI  0x00010000
#define MASK_ERR_COUNT_HI 0x00000FFF
#define MASK_BLKPTR_LO    0xFF000000
#define MCG_XBLK_ADDR     0xC0000400

/* Deferred error settings */
#define MSR_CU_DEF_ERR          0xC0000410
#define MASK_DEF_LVTOFF         0x000000F0

/* Scalable MCA: */

/* Threshold LVT offset is at MSR0xC0000410[15:12] */
#define SMCA_THR_LVT_OFF        0xF000

static bool thresholding_irq_en;

struct mce_amd_cpu_data {
        mce_banks_t     thr_intr_banks;
        mce_banks_t     dfr_intr_banks;

        u32             thr_intr_en: 1,
                        dfr_intr_en: 1,
                        __resv: 30;
};

static DEFINE_PER_CPU_READ_MOSTLY(struct mce_amd_cpu_data, mce_amd_data);

static const char * const th_names[] = {
        "load_store",
        "insn_fetch",
        "combined_unit",
        "decode_unit",
        "northbridge",
        "execution_unit",
};

static const char * const smca_umc_block_names[] = {
        "dram_ecc",
        "misc_umc"
};

#define HWID_MCATYPE(hwid, mcatype) (((hwid) << 16) | (mcatype))

struct smca_hwid {
        unsigned int bank_type; /* Use with smca_bank_types for easy indexing. */
        u32 hwid_mcatype;       /* (hwid,mcatype) tuple */
};

struct smca_bank {
        const struct smca_hwid *hwid;
        u32 id;                 /* Value of MCA_IPID[InstanceId]. */
        u8 sysfs_id;            /* Value used for sysfs name. */
        u64 paddrv      :1,     /* Physical Address Valid bit in MCA_CONFIG */
            __reserved  :63;
};

static DEFINE_PER_CPU_READ_MOSTLY(struct smca_bank[MAX_NR_BANKS], smca_banks);
static DEFINE_PER_CPU_READ_MOSTLY(u8[N_SMCA_BANK_TYPES], smca_bank_counts);

static const char * const smca_names[] = {
        [SMCA_LS ... SMCA_LS_V2]        = "load_store",
        [SMCA_IF]                       = "insn_fetch",
        [SMCA_L2_CACHE]                 = "l2_cache",
        [SMCA_DE]                       = "decode_unit",
        [SMCA_RESERVED]                 = "reserved",
        [SMCA_EX]                       = "execution_unit",
        [SMCA_FP]                       = "floating_point",
        [SMCA_L3_CACHE]                 = "l3_cache",
        [SMCA_CS ... SMCA_CS_V2]        = "coherent_slave",
        [SMCA_PIE]                      = "pie",

        /* UMC v2 is separate because both of them can exist in a single system. */
        [SMCA_UMC]                      = "umc",
        [SMCA_UMC_V2]                   = "umc_v2",
        [SMCA_MA_LLC]                   = "ma_llc",
        [SMCA_PB]                       = "param_block",
        [SMCA_PSP ... SMCA_PSP_V2]      = "psp",
        [SMCA_SMU ... SMCA_SMU_V2]      = "smu",
        [SMCA_MP5]                      = "mp5",
        [SMCA_MPDMA]                    = "mpdma",
        [SMCA_NBIO]                     = "nbio",
        [SMCA_PCIE ... SMCA_PCIE_V2]    = "pcie",
        [SMCA_XGMI_PCS]                 = "xgmi_pcs",
        [SMCA_NBIF]                     = "nbif",
        [SMCA_SHUB]                     = "shub",
        [SMCA_SATA]                     = "sata",
        [SMCA_USB]                      = "usb",
        [SMCA_USR_DP]                   = "usr_dp",
        [SMCA_USR_CP]                   = "usr_cp",
        [SMCA_GMI_PCS]                  = "gmi_pcs",
        [SMCA_XGMI_PHY]                 = "xgmi_phy",
        [SMCA_WAFL_PHY]                 = "wafl_phy",
        [SMCA_GMI_PHY]                  = "gmi_phy",
};

static const char *smca_get_name(enum smca_bank_types t)
{
        if (t >= N_SMCA_BANK_TYPES)
                return NULL;

        return smca_names[t];
}

enum smca_bank_types smca_get_bank_type(unsigned int cpu, unsigned int bank)
{
        struct smca_bank *b;

        if (bank >= MAX_NR_BANKS)
                return N_SMCA_BANK_TYPES;

        b = &per_cpu(smca_banks, cpu)[bank];
        if (!b->hwid)
                return N_SMCA_BANK_TYPES;

        return b->hwid->bank_type;
}
EXPORT_SYMBOL_GPL(smca_get_bank_type);

static const struct smca_hwid smca_hwid_mcatypes[] = {
        /* { bank_type, hwid_mcatype } */

        /* Reserved type */
        { SMCA_RESERVED, HWID_MCATYPE(0x00, 0x0)        },

        /* ZN Core (HWID=0xB0) MCA types */
        { SMCA_LS,       HWID_MCATYPE(0xB0, 0x0)        },
        { SMCA_LS_V2,    HWID_MCATYPE(0xB0, 0x10)       },
        { SMCA_IF,       HWID_MCATYPE(0xB0, 0x1)        },
        { SMCA_L2_CACHE, HWID_MCATYPE(0xB0, 0x2)        },
        { SMCA_DE,       HWID_MCATYPE(0xB0, 0x3)        },
        /* HWID 0xB0 MCATYPE 0x4 is Reserved */
        { SMCA_EX,       HWID_MCATYPE(0xB0, 0x5)        },
        { SMCA_FP,       HWID_MCATYPE(0xB0, 0x6)        },
        { SMCA_L3_CACHE, HWID_MCATYPE(0xB0, 0x7)        },

        /* Data Fabric MCA types */
        { SMCA_CS,       HWID_MCATYPE(0x2E, 0x0)        },
        { SMCA_PIE,      HWID_MCATYPE(0x2E, 0x1)        },
        { SMCA_CS_V2,    HWID_MCATYPE(0x2E, 0x2)        },
        { SMCA_MA_LLC,   HWID_MCATYPE(0x2E, 0x4)        },

        /* Unified Memory Controller MCA type */
        { SMCA_UMC,      HWID_MCATYPE(0x96, 0x0)        },
        { SMCA_UMC_V2,   HWID_MCATYPE(0x96, 0x1)        },

        /* Parameter Block MCA type */
        { SMCA_PB,       HWID_MCATYPE(0x05, 0x0)        },

        /* Platform Security Processor MCA type */
        { SMCA_PSP,      HWID_MCATYPE(0xFF, 0x0)        },
        { SMCA_PSP_V2,   HWID_MCATYPE(0xFF, 0x1)        },

        /* System Management Unit MCA type */
        { SMCA_SMU,      HWID_MCATYPE(0x01, 0x0)        },
        { SMCA_SMU_V2,   HWID_MCATYPE(0x01, 0x1)        },

        /* Microprocessor 5 Unit MCA type */
        { SMCA_MP5,      HWID_MCATYPE(0x01, 0x2)        },

        /* MPDMA MCA type */
        { SMCA_MPDMA,    HWID_MCATYPE(0x01, 0x3)        },

        /* Northbridge IO Unit MCA type */
        { SMCA_NBIO,     HWID_MCATYPE(0x18, 0x0)        },

        /* PCI Express Unit MCA type */
        { SMCA_PCIE,     HWID_MCATYPE(0x46, 0x0)        },
        { SMCA_PCIE_V2,  HWID_MCATYPE(0x46, 0x1)        },

        { SMCA_XGMI_PCS, HWID_MCATYPE(0x50, 0x0)        },
        { SMCA_NBIF,     HWID_MCATYPE(0x6C, 0x0)        },
        { SMCA_SHUB,     HWID_MCATYPE(0x80, 0x0)        },
        { SMCA_SATA,     HWID_MCATYPE(0xA8, 0x0)        },
        { SMCA_USB,      HWID_MCATYPE(0xAA, 0x0)        },
        { SMCA_USR_DP,   HWID_MCATYPE(0x170, 0x0)       },
        { SMCA_USR_CP,   HWID_MCATYPE(0x180, 0x0)       },
        { SMCA_GMI_PCS,  HWID_MCATYPE(0x241, 0x0)       },
        { SMCA_XGMI_PHY, HWID_MCATYPE(0x259, 0x0)       },
        { SMCA_WAFL_PHY, HWID_MCATYPE(0x267, 0x0)       },
        { SMCA_GMI_PHY,  HWID_MCATYPE(0x269, 0x0)       },
};

/*
 * In SMCA enabled processors, we can have multiple banks for a given IP type.
 * So to define a unique name for each bank, we use a temp c-string to append
 * the MCA_IPID[InstanceId] to type's name in get_name().
 *
 * InstanceId is 32 bits which is 8 characters. Make sure MAX_MCATYPE_NAME_LEN
 * is greater than 8 plus 1 (for underscore) plus length of longest type name.
 */
#define MAX_MCATYPE_NAME_LEN    30
static char buf_mcatype[MAX_MCATYPE_NAME_LEN];

struct threshold_block {
        /* This block's number within its bank. */
        unsigned int            block;
        /* MCA bank number that contains this block. */
        unsigned int            bank;
        /* CPU which controls this block's MCA bank. */
        unsigned int            cpu;
        /* MCA_MISC MSR address for this block. */
        u32                     address;
        /* Enable/Disable APIC interrupt. */
        bool                    interrupt_enable;
        /* Bank can generate an interrupt. */
        bool                    interrupt_capable;
        /* Value upon which threshold interrupt is generated. */
        u16                     threshold_limit;
        /* sysfs object */
        struct kobject          kobj;
        /* List of threshold blocks within this block's MCA bank. */
        struct list_head        miscj;
};

struct threshold_bank {
        struct kobject          *kobj;
        /* List of threshold blocks within this MCA bank. */
        struct list_head        miscj;
};

static DEFINE_PER_CPU(struct threshold_bank **, threshold_banks);

/*
 * A list of the banks enabled on each logical CPU. Controls which respective
 * descriptors to initialize later in mce_threshold_create_device().
 */
static DEFINE_PER_CPU(u64, bank_map);

static void amd_threshold_interrupt(void);
static void amd_deferred_error_interrupt(void);

static void default_deferred_error_interrupt(void)
{
        pr_err("Unexpected deferred interrupt at vector %x\n", DEFERRED_ERROR_VECTOR);
}
void (*deferred_error_int_vector)(void) = default_deferred_error_interrupt;

static void smca_configure(unsigned int bank, unsigned int cpu)
{
        struct mce_amd_cpu_data *data = this_cpu_ptr(&mce_amd_data);
        u8 *bank_counts = this_cpu_ptr(smca_bank_counts);
        const struct smca_hwid *s_hwid;
        unsigned int i, hwid_mcatype;
        u32 high, low;
        u32 smca_config = MSR_AMD64_SMCA_MCx_CONFIG(bank);

        /* Set appropriate bits in MCA_CONFIG */
        if (!rdmsr_safe(smca_config, &low, &high)) {
                /*
                 * OS is required to set the MCAX bit to acknowledge that it is
                 * now using the new MSR ranges and new registers under each
                 * bank. It also means that the OS will configure deferred
                 * errors in the new MCx_CONFIG register. If the bit is not set,
                 * uncorrectable errors will cause a system panic.
                 *
                 * MCA_CONFIG[MCAX] is bit 32 (0 in the high portion of the MSR.)
                 */
                high |= BIT(0);

                /*
                 * SMCA sets the Deferred Error Interrupt type per bank.
                 *
                 * MCA_CONFIG[DeferredIntTypeSupported] is bit 5, and tells us
                 * if the DeferredIntType bit field is available.
                 *
                 * MCA_CONFIG[DeferredIntType] is bits [38:37] ([6:5] in the
                 * high portion of the MSR). OS should set this to 0x1 to enable
                 * APIC based interrupt. First, check that no interrupt has been
                 * set.
                 */
                if ((low & BIT(5)) && !((high >> 5) & 0x3) && data->dfr_intr_en) {
                        __set_bit(bank, data->dfr_intr_banks);
                        high |= BIT(5);
                }

                /*
                 * SMCA Corrected Error Interrupt
                 *
                 * MCA_CONFIG[IntPresent] is bit 10, and tells us if the bank can
                 * send an MCA Thresholding interrupt without the OS initializing
                 * this feature. This can be used if the threshold limit is managed
                 * by the platform.
                 *
                 * MCA_CONFIG[IntEn] is bit 40 (8 in the high portion of the MSR).
                 * The OS should set this to inform the platform that the OS is ready
                 * to handle the MCA Thresholding interrupt.
                 */
                if ((low & BIT(10)) && data->thr_intr_en) {
                        __set_bit(bank, data->thr_intr_banks);
                        high |= BIT(8);
                }

                this_cpu_ptr(mce_banks_array)[bank].lsb_in_status = !!(low & BIT(8));

                if (low & MCI_CONFIG_PADDRV)
                        this_cpu_ptr(smca_banks)[bank].paddrv = 1;

                wrmsr(smca_config, low, high);
        }

        if (rdmsr_safe(MSR_AMD64_SMCA_MCx_IPID(bank), &low, &high)) {
                pr_warn("Failed to read MCA_IPID for bank %d\n", bank);
                return;
        }

        hwid_mcatype = HWID_MCATYPE(high & MCI_IPID_HWID,
                                    (high & MCI_IPID_MCATYPE) >> 16);

        for (i = 0; i < ARRAY_SIZE(smca_hwid_mcatypes); i++) {
                s_hwid = &smca_hwid_mcatypes[i];

                if (hwid_mcatype == s_hwid->hwid_mcatype) {
                        this_cpu_ptr(smca_banks)[bank].hwid = s_hwid;
                        this_cpu_ptr(smca_banks)[bank].id = low;
                        this_cpu_ptr(smca_banks)[bank].sysfs_id = bank_counts[s_hwid->bank_type]++;
                        break;
                }
        }
}

struct thresh_restart {
        struct threshold_block  *b;
        int                     set_lvt_off;
        int                     lvt_off;
        u16                     old_limit;
};

static const char *bank4_names(const struct threshold_block *b)
{
        switch (b->address) {
        /* MSR4_MISC0 */
        case 0x00000413:
                return "dram";

        case 0xc0000408:
                return "ht_links";

        case 0xc0000409:
                return "l3_cache";

        default:
                WARN(1, "Funny MSR: 0x%08x\n", b->address);
                return "";
        }
};


static bool lvt_interrupt_supported(unsigned int bank, u32 msr_high_bits)
{
        /*
         * bank 4 supports APIC LVT interrupts implicitly since forever.
         */
        if (bank == 4)
                return true;

        /*
         * IntP: interrupt present; if this bit is set, the thresholding
         * bank can generate APIC LVT interrupts
         */
        return msr_high_bits & BIT(28);
}

static bool lvt_off_valid(struct threshold_block *b, int apic, u32 lo, u32 hi)
{
        int msr = (hi & MASK_LVTOFF_HI) >> 20;

        /*
         * On SMCA CPUs, LVT offset is programmed at a different MSR, and
         * the BIOS provides the value. The original field where LVT offset
         * was set is reserved. Return early here:
         */
        if (mce_flags.smca)
                return false;

        if (apic < 0) {
                pr_err(FW_BUG "cpu %d, failed to setup threshold interrupt "
                       "for bank %d, block %d (MSR%08X=0x%x%08x)\n", b->cpu,
                       b->bank, b->block, b->address, hi, lo);
                return false;
        }

        if (apic != msr) {
                pr_err(FW_BUG "cpu %d, invalid threshold interrupt offset %d "
                       "for bank %d, block %d (MSR%08X=0x%x%08x)\n",
                       b->cpu, apic, b->bank, b->block, b->address, hi, lo);
                return false;
        }

        return true;
};

/* Reprogram MCx_MISC MSR behind this threshold block. */
static void threshold_restart_block(void *_tr)
{
        struct thresh_restart *tr = _tr;
        u32 hi, lo;

        /* sysfs write might race against an offline operation */
        if (!this_cpu_read(threshold_banks) && !tr->set_lvt_off)
                return;

        rdmsr(tr->b->address, lo, hi);

        /*
         * Reset error count and overflow bit.
         * This is done during init or after handling an interrupt.
         */
        if (hi & MASK_OVERFLOW_HI || tr->set_lvt_off) {
                hi &= ~(MASK_ERR_COUNT_HI | MASK_OVERFLOW_HI);
                hi |= THRESHOLD_MAX - tr->b->threshold_limit;
        } else if (tr->old_limit) {     /* change limit w/o reset */
                int new_count = (hi & THRESHOLD_MAX) +
                    (tr->old_limit - tr->b->threshold_limit);

                hi = (hi & ~MASK_ERR_COUNT_HI) |
                    (new_count & THRESHOLD_MAX);
        }

        /* clear IntType */
        hi &= ~MASK_INT_TYPE_HI;

        if (!tr->b->interrupt_capable)
                goto done;

        if (tr->set_lvt_off) {
                if (lvt_off_valid(tr->b, tr->lvt_off, lo, hi)) {
                        /* set new lvt offset */
                        hi &= ~MASK_LVTOFF_HI;
                        hi |= tr->lvt_off << 20;
                }
        }

        if (tr->b->interrupt_enable)
                hi |= INT_TYPE_APIC;

 done:

        hi |= MASK_COUNT_EN_HI;
        wrmsr(tr->b->address, lo, hi);
}

static void threshold_restart_bank(unsigned int bank, bool intr_en)
{
        struct threshold_bank **thr_banks = this_cpu_read(threshold_banks);
        struct threshold_block *block, *tmp;
        struct thresh_restart tr;

        if (!thr_banks || !thr_banks[bank])
                return;

        memset(&tr, 0, sizeof(tr));

        list_for_each_entry_safe(block, tmp, &thr_banks[bank]->miscj, miscj) {
                tr.b = block;
                tr.b->interrupt_enable = intr_en;
                threshold_restart_block(&tr);
        }
}

/* Try to use the threshold limit reported through APEI. */
static u16 get_thr_limit(void)
{
        u32 thr_limit = mce_get_apei_thr_limit();

        /* Fallback to old default if APEI limit is not available. */
        if (!thr_limit)
                return THRESHOLD_MAX;

        return min(thr_limit, THRESHOLD_MAX);
}

static void mce_threshold_block_init(struct threshold_block *b, int offset)
{
        struct thresh_restart tr = {
                .b                      = b,
                .set_lvt_off            = 1,
                .lvt_off                = offset,
        };

        b->threshold_limit              = get_thr_limit();
        threshold_restart_block(&tr);
};

static int setup_APIC_mce_threshold(int reserved, int new)
{
        if (reserved < 0 && !setup_APIC_eilvt(new, THRESHOLD_APIC_VECTOR,
                                              APIC_EILVT_MSG_FIX, 0))
                return new;

        return reserved;
}

static u32 get_block_address(u32 current_addr, u32 low, u32 high,
                             unsigned int bank, unsigned int block,
                             unsigned int cpu)
{
        u32 addr = 0, offset = 0;

        if ((bank >= per_cpu(mce_num_banks, cpu)) || (block >= NR_BLOCKS))
                return addr;

        if (mce_flags.smca) {
                if (!block)
                        return MSR_AMD64_SMCA_MCx_MISC(bank);

                if (!(low & MASK_BLKPTR_LO))
                        return 0;

                return MSR_AMD64_SMCA_MCx_MISCy(bank, block - 1);
        }

        /* Fall back to method we used for older processors: */
        switch (block) {
        case 0:
                addr = mca_msr_reg(bank, MCA_MISC);
                break;
        case 1:
                offset = ((low & MASK_BLKPTR_LO) >> 21);
                if (offset)
                        addr = MCG_XBLK_ADDR + offset;
                break;
        default:
                addr = ++current_addr;
        }
        return addr;
}

static int prepare_threshold_block(unsigned int bank, unsigned int block, u32 addr,
                                   int offset, u32 misc_high)
{
        unsigned int cpu = smp_processor_id();
        struct threshold_block b;
        int new;

        if (!block)
                per_cpu(bank_map, cpu) |= BIT_ULL(bank);

        memset(&b, 0, sizeof(b));
        b.cpu                   = cpu;
        b.bank                  = bank;
        b.block                 = block;
        b.address               = addr;
        b.interrupt_capable     = lvt_interrupt_supported(bank, misc_high);

        if (!b.interrupt_capable)
                goto done;

        __set_bit(bank, this_cpu_ptr(&mce_amd_data)->thr_intr_banks);
        b.interrupt_enable = 1;

        if (mce_flags.smca)
                goto done;

        new = (misc_high & MASK_LVTOFF_HI) >> 20;
        offset = setup_APIC_mce_threshold(offset, new);
        if (offset == new)
                thresholding_irq_en = true;

done:
        mce_threshold_block_init(&b, offset);

        return offset;
}

bool amd_filter_mce(struct mce *m)
{
        enum smca_bank_types bank_type = smca_get_bank_type(m->extcpu, m->bank);
        struct cpuinfo_x86 *c = &boot_cpu_data;

        /* See Family 17h Models 10h-2Fh Erratum #1114. */
        if (c->x86 == 0x17 &&
            c->x86_model >= 0x10 && c->x86_model <= 0x2F &&
            bank_type == SMCA_IF && XEC(m->status, 0x3f) == 10)
                return true;

        /* NB GART TLB error reporting is disabled by default. */
        if (c->x86 < 0x17) {
                if (m->bank == 4 && XEC(m->status, 0x1f) == 0x5)
                        return true;
        }

        return false;
}

/*
 * Turn off thresholding banks for the following conditions:
 * - MC4_MISC thresholding is not supported on Family 0x15.
 * - Prevent possible spurious interrupts from the IF bank on Family 0x17
 *   Models 0x10-0x2F due to Erratum #1114.
 */
static void disable_err_thresholding(struct cpuinfo_x86 *c, unsigned int bank)
{
        int i, num_msrs;
        u64 hwcr;
        bool need_toggle;
        u32 msrs[NR_BLOCKS];

        if (c->x86 == 0x15 && bank == 4) {
                msrs[0] = 0x00000413; /* MC4_MISC0 */
                msrs[1] = 0xc0000408; /* MC4_MISC1 */
                num_msrs = 2;
        } else if (c->x86 == 0x17 &&
                   (c->x86_model >= 0x10 && c->x86_model <= 0x2F)) {

                if (smca_get_bank_type(smp_processor_id(), bank) != SMCA_IF)
                        return;

                msrs[0] = MSR_AMD64_SMCA_MCx_MISC(bank);
                num_msrs = 1;
        } else {
                return;
        }

        rdmsrq(MSR_K7_HWCR, hwcr);

        /* McStatusWrEn has to be set */
        need_toggle = !(hwcr & BIT(18));
        if (need_toggle)
                wrmsrq(MSR_K7_HWCR, hwcr | BIT(18));

        /* Clear CntP bit safely */
        for (i = 0; i < num_msrs; i++)
                msr_clear_bit(msrs[i], 62);

        /* restore old settings */
        if (need_toggle)
                wrmsrq(MSR_K7_HWCR, hwcr);
}

static void amd_apply_cpu_quirks(struct cpuinfo_x86 *c)
{
        struct mce_bank *mce_banks = this_cpu_ptr(mce_banks_array);

        /* This should be disabled by the BIOS, but isn't always */
        if (c->x86 == 15 && this_cpu_read(mce_num_banks) > 4) {
                /*
                 * disable GART TBL walk error reporting, which
                 * trips off incorrectly with the IOMMU & 3ware
                 * & Cerberus:
                 */
                clear_bit(10, (unsigned long *)&mce_banks[4].ctl);
        }

        /*
         * Various K7s with broken bank 0 around. Always disable
         * by default.
         */
        if (c->x86 == 6 && this_cpu_read(mce_num_banks))
                mce_banks[0].ctl = 0;
}

/*
 * Enable the APIC LVT interrupt vectors once per-CPU. This should be done before hardware is
 * ready to send interrupts.
 *
 * Individual error sources are enabled later during per-bank init.
 */
static void smca_enable_interrupt_vectors(void)
{
        struct mce_amd_cpu_data *data = this_cpu_ptr(&mce_amd_data);
        u64 mca_intr_cfg, offset;

        if (!mce_flags.smca || !mce_flags.succor)
                return;

        if (rdmsrq_safe(MSR_CU_DEF_ERR, &mca_intr_cfg))
                return;

        offset = (mca_intr_cfg & SMCA_THR_LVT_OFF) >> 12;
        if (!setup_APIC_eilvt(offset, THRESHOLD_APIC_VECTOR, APIC_EILVT_MSG_FIX, 0))
                data->thr_intr_en = 1;

        offset = (mca_intr_cfg & MASK_DEF_LVTOFF) >> 4;
        if (!setup_APIC_eilvt(offset, DEFERRED_ERROR_VECTOR, APIC_EILVT_MSG_FIX, 0))
                data->dfr_intr_en = 1;
}

/* cpu init entry point, called from mce.c with preempt off */
void mce_amd_feature_init(struct cpuinfo_x86 *c)
{
        unsigned int bank, block, cpu = smp_processor_id();
        u32 low = 0, high = 0, address = 0;
        int offset = -1;

        amd_apply_cpu_quirks(c);

        mce_flags.amd_threshold  = 1;

        smca_enable_interrupt_vectors();

        for (bank = 0; bank < this_cpu_read(mce_num_banks); ++bank) {
                if (mce_flags.smca) {
                        smca_configure(bank, cpu);

                        if (!this_cpu_ptr(&mce_amd_data)->thr_intr_en)
                                continue;
                }

                disable_err_thresholding(c, bank);

                for (block = 0; block < NR_BLOCKS; ++block) {
                        address = get_block_address(address, low, high, bank, block, cpu);
                        if (!address)
                                break;

                        if (rdmsr_safe(address, &low, &high))
                                break;

                        if (!(high & MASK_VALID_HI))
                                continue;

                        if (!(high & MASK_CNTP_HI)  ||
                             (high & MASK_LOCKED_HI))
                                continue;

                        offset = prepare_threshold_block(bank, block, address, offset, high);
                }
        }
}

void smca_bsp_init(void)
{
        mce_threshold_vector      = amd_threshold_interrupt;
        deferred_error_int_vector = amd_deferred_error_interrupt;
}

/*
 * DRAM ECC errors are reported in the Northbridge (bank 4) with
 * Extended Error Code 8.
 */
static bool legacy_mce_is_memory_error(struct mce *m)
{
        return m->bank == 4 && XEC(m->status, 0x1f) == 8;
}

/*
 * DRAM ECC errors are reported in Unified Memory Controllers with
 * Extended Error Code 0.
 */
static bool smca_mce_is_memory_error(struct mce *m)
{
        enum smca_bank_types bank_type;

        if (XEC(m->status, 0x3f))
                return false;

        bank_type = smca_get_bank_type(m->extcpu, m->bank);

        return bank_type == SMCA_UMC || bank_type == SMCA_UMC_V2;
}

bool amd_mce_is_memory_error(struct mce *m)
{
        if (mce_flags.smca)
                return smca_mce_is_memory_error(m);
        else
                return legacy_mce_is_memory_error(m);
}

/*
 * Some AMD systems have an explicit indicator that the value in MCA_ADDR is a
 * system physical address. Individual cases though, need to be detected for
 * other systems. Future cases will be added as needed.
 *
 * 1) General case
 *      a) Assume address is not usable.
 * 2) Poison errors
 *      a) Indicated by MCA_STATUS[43]: poison. Defined for all banks except legacy
 *         northbridge (bank 4).
 *      b) Refers to poison consumption in the core. Does not include "no action",
 *         "action optional", or "deferred" error severities.
 *      c) Will include a usable address so that immediate action can be taken.
 * 3) Northbridge DRAM ECC errors
 *      a) Reported in legacy bank 4 with extended error code (XEC) 8.
 *      b) MCA_STATUS[43] is *not* defined as poison in legacy bank 4. Therefore,
 *         this bit should not be checked.
 * 4) MCI_STATUS_PADDRVAL is set
 *      a) Will provide a valid system physical address.
 *
 * NOTE: SMCA UMC memory errors fall into case #1.
 */
bool amd_mce_usable_address(struct mce *m)
{
        /* Check special northbridge case 3) first. */
        if (!mce_flags.smca) {
                if (legacy_mce_is_memory_error(m))
                        return true;
                else if (m->bank == 4)
                        return false;
        }

        if (this_cpu_ptr(smca_banks)[m->bank].paddrv)
                return m->status & MCI_STATUS_PADDRV;

        /* Check poison bit for all other bank types. */
        if (m->status & MCI_STATUS_POISON)
                return true;

        /* Assume address is not usable for all others. */
        return false;
}

DEFINE_IDTENTRY_SYSVEC(sysvec_deferred_error)
{
        trace_deferred_error_apic_entry(DEFERRED_ERROR_VECTOR);
        inc_irq_stat(irq_deferred_error_count);
        deferred_error_int_vector();
        trace_deferred_error_apic_exit(DEFERRED_ERROR_VECTOR);
        apic_eoi();
}

/* APIC interrupt handler for deferred errors */
static void amd_deferred_error_interrupt(void)
{
        machine_check_poll(MCP_TIMESTAMP, &this_cpu_ptr(&mce_amd_data)->dfr_intr_banks);
}

void mce_amd_handle_storm(unsigned int bank, bool on)
{
        threshold_restart_bank(bank, on);
}

static void amd_reset_thr_limit(unsigned int bank)
{
        threshold_restart_bank(bank, true);
}

/*
 * Threshold interrupt handler will service THRESHOLD_APIC_VECTOR. The interrupt
 * goes off when error_count reaches threshold_limit.
 */
static void amd_threshold_interrupt(void)
{
        machine_check_poll(MCP_TIMESTAMP, &this_cpu_ptr(&mce_amd_data)->thr_intr_banks);
}

void amd_clear_bank(struct mce *m)
{
        amd_reset_thr_limit(m->bank);

        if (mce_flags.smca) {
                /*
                 * Clear MCA_DESTAT for all deferred errors even those
                 * logged in MCA_STATUS.
                 */
                if (m->status & MCI_STATUS_DEFERRED)
                        mce_wrmsrq(MSR_AMD64_SMCA_MCx_DESTAT(m->bank), 0);

                /* Don't clear MCA_STATUS if MCA_DESTAT was used exclusively. */
                if (m->kflags & MCE_CHECK_DFR_REGS)
                        return;
        }

        mce_wrmsrq(mca_msr_reg(m->bank, MCA_STATUS), 0);
}

/*
 * Sysfs Interface
 */

struct threshold_attr {
        struct attribute attr;
        ssize_t (*show) (struct threshold_block *, char *);
        ssize_t (*store) (struct threshold_block *, const char *, size_t count);
};

#define SHOW_FIELDS(name)                                               \
static ssize_t show_ ## name(struct threshold_block *b, char *buf)      \
{                                                                       \
        return sprintf(buf, "%lu\n", (unsigned long) b->name);          \
}
SHOW_FIELDS(interrupt_enable)
SHOW_FIELDS(threshold_limit)

static ssize_t
store_interrupt_enable(struct threshold_block *b, const char *buf, size_t size)
{
        struct thresh_restart tr;
        unsigned long new;

        if (!b->interrupt_capable)
                return -EINVAL;

        if (kstrtoul(buf, 0, &new) < 0)
                return -EINVAL;

        b->interrupt_enable = !!new;

        memset(&tr, 0, sizeof(tr));
        tr.b            = b;

        if (smp_call_function_single(b->cpu, threshold_restart_block, &tr, 1))
                return -ENODEV;

        return size;
}

static ssize_t
store_threshold_limit(struct threshold_block *b, const char *buf, size_t size)
{
        struct thresh_restart tr;
        unsigned long new;

        if (kstrtoul(buf, 0, &new) < 0)
                return -EINVAL;

        if (new > THRESHOLD_MAX)
                new = THRESHOLD_MAX;
        if (new < 1)
                new = 1;

        memset(&tr, 0, sizeof(tr));
        tr.old_limit = b->threshold_limit;
        b->threshold_limit = new;
        tr.b = b;

        if (smp_call_function_single(b->cpu, threshold_restart_block, &tr, 1))
                return -ENODEV;

        return size;
}

static ssize_t show_error_count(struct threshold_block *b, char *buf)
{
        u32 lo, hi;

        /* CPU might be offline by now */
        if (rdmsr_on_cpu(b->cpu, b->address, &lo, &hi))
                return -ENODEV;

        return sprintf(buf, "%u\n", ((hi & THRESHOLD_MAX) -
                                     (THRESHOLD_MAX - b->threshold_limit)));
}

static struct threshold_attr error_count = {
        .attr = {.name = __stringify(error_count), .mode = 0444 },
        .show = show_error_count,
};

#define RW_ATTR(val)                                                    \
static struct threshold_attr val = {                                    \
        .attr   = {.name = __stringify(val), .mode = 0644 },            \
        .show   = show_## val,                                          \
        .store  = store_## val,                                         \
};

RW_ATTR(interrupt_enable);
RW_ATTR(threshold_limit);

static struct attribute *default_attrs[] = {
        &threshold_limit.attr,
        &error_count.attr,
        NULL,   /* possibly interrupt_enable if supported, see below */
        NULL,
};
ATTRIBUTE_GROUPS(default);

#define to_block(k)     container_of(k, struct threshold_block, kobj)
#define to_attr(a)      container_of(a, struct threshold_attr, attr)

static ssize_t show(struct kobject *kobj, struct attribute *attr, char *buf)
{
        struct threshold_block *b = to_block(kobj);
        struct threshold_attr *a = to_attr(attr);
        ssize_t ret;

        ret = a->show ? a->show(b, buf) : -EIO;

        return ret;
}

static ssize_t store(struct kobject *kobj, struct attribute *attr,
                     const char *buf, size_t count)
{
        struct threshold_block *b = to_block(kobj);
        struct threshold_attr *a = to_attr(attr);
        ssize_t ret;

        ret = a->store ? a->store(b, buf, count) : -EIO;

        return ret;
}

static const struct sysfs_ops threshold_ops = {
        .show                   = show,
        .store                  = store,
};

static void threshold_block_release(struct kobject *kobj);

static const struct kobj_type threshold_ktype = {
        .sysfs_ops              = &threshold_ops,
        .default_groups         = default_groups,
        .release                = threshold_block_release,
};

static const char *get_name(unsigned int cpu, unsigned int bank, struct threshold_block *b)
{
        enum smca_bank_types bank_type;

        if (!mce_flags.smca) {
                if (b && bank == 4)
                        return bank4_names(b);

                return th_names[bank];
        }

        bank_type = smca_get_bank_type(cpu, bank);

        if (b && (bank_type == SMCA_UMC || bank_type == SMCA_UMC_V2)) {
                if (b->block < ARRAY_SIZE(smca_umc_block_names))
                        return smca_umc_block_names[b->block];
        }

        if (b && b->block) {
                snprintf(buf_mcatype, MAX_MCATYPE_NAME_LEN, "th_block_%u", b->block);
                return buf_mcatype;
        }

        if (bank_type >= N_SMCA_BANK_TYPES) {
                snprintf(buf_mcatype, MAX_MCATYPE_NAME_LEN, "th_bank_%u", bank);
                return buf_mcatype;
        }

        if (per_cpu(smca_bank_counts, cpu)[bank_type] == 1)
                return smca_get_name(bank_type);

        snprintf(buf_mcatype, MAX_MCATYPE_NAME_LEN,
                 "%s_%u", smca_get_name(bank_type),
                          per_cpu(smca_banks, cpu)[bank].sysfs_id);
        return buf_mcatype;
}

static int allocate_threshold_blocks(unsigned int cpu, struct threshold_bank *tb,
                                     unsigned int bank, unsigned int block,
                                     u32 address)
{
        struct threshold_block *b = NULL;
        u32 low, high;
        int err;

        if ((bank >= this_cpu_read(mce_num_banks)) || (block >= NR_BLOCKS))
                return 0;

        if (rdmsr_safe(address, &low, &high))
                return 0;

        if (!(high & MASK_VALID_HI)) {
                if (block)
                        goto recurse;
                else
                        return 0;
        }

        if (!(high & MASK_CNTP_HI)  ||
             (high & MASK_LOCKED_HI))
                goto recurse;

        b = kzalloc_obj(struct threshold_block);
        if (!b)
                return -ENOMEM;

        b->block                = block;
        b->bank                 = bank;
        b->cpu                  = cpu;
        b->address              = address;
        b->interrupt_enable     = 0;
        b->interrupt_capable    = lvt_interrupt_supported(bank, high);
        b->threshold_limit      = get_thr_limit();

        if (b->interrupt_capable) {
                default_attrs[2] = &interrupt_enable.attr;
                b->interrupt_enable = 1;
        } else {
                default_attrs[2] = NULL;
        }

        list_add(&b->miscj, &tb->miscj);

        mce_threshold_block_init(b, (high & MASK_LVTOFF_HI) >> 20);

        err = kobject_init_and_add(&b->kobj, &threshold_ktype, tb->kobj, get_name(cpu, bank, b));
        if (err)
                goto out_free;
recurse:
        address = get_block_address(address, low, high, bank, ++block, cpu);
        if (!address)
                return 0;

        err = allocate_threshold_blocks(cpu, tb, bank, block, address);
        if (err)
                goto out_free;

        if (b)
                kobject_uevent(&b->kobj, KOBJ_ADD);

        return 0;

out_free:
        if (b) {
                list_del(&b->miscj);
                kobject_put(&b->kobj);
        }
        return err;
}

static int threshold_create_bank(struct threshold_bank **bp, unsigned int cpu,
                                 unsigned int bank)
{
        struct device *dev = this_cpu_read(mce_device);
        struct threshold_bank *b = NULL;
        const char *name = get_name(cpu, bank, NULL);
        int err = 0;

        if (!dev)
                return -ENODEV;

        b = kzalloc_obj(struct threshold_bank);
        if (!b) {
                err = -ENOMEM;
                goto out;
        }

        /* Associate the bank with the per-CPU MCE device */
        b->kobj = kobject_create_and_add(name, &dev->kobj);
        if (!b->kobj) {
                err = -EINVAL;
                goto out_free;
        }

        INIT_LIST_HEAD(&b->miscj);

        err = allocate_threshold_blocks(cpu, b, bank, 0, mca_msr_reg(bank, MCA_MISC));
        if (err)
                goto out_kobj;

        bp[bank] = b;
        return 0;

out_kobj:
        kobject_put(b->kobj);
out_free:
        kfree(b);
out:
        return err;
}

static void threshold_block_release(struct kobject *kobj)
{
        kfree(to_block(kobj));
}

static void threshold_remove_bank(struct threshold_bank *bank)
{
        struct threshold_block *pos, *tmp;

        list_for_each_entry_safe(pos, tmp, &bank->miscj, miscj) {
                list_del(&pos->miscj);
                kobject_put(&pos->kobj);
        }

        kobject_put(bank->kobj);
        kfree(bank);
}

static void __threshold_remove_device(struct threshold_bank **bp)
{
        unsigned int bank, numbanks = this_cpu_read(mce_num_banks);

        for (bank = 0; bank < numbanks; bank++) {
                if (!bp[bank])
                        continue;

                threshold_remove_bank(bp[bank]);
                bp[bank] = NULL;
        }
        kfree(bp);
}

void mce_threshold_remove_device(unsigned int cpu)
{
        struct threshold_bank **bp = this_cpu_read(threshold_banks);

        if (!bp)
                return;

        /*
         * Clear the pointer before cleaning up, so that the interrupt won't
         * touch anything of this.
         */
        this_cpu_write(threshold_banks, NULL);

        __threshold_remove_device(bp);
        return;
}

/**
 * mce_threshold_create_device - Create the per-CPU MCE threshold device
 * @cpu:        The plugged in CPU
 *
 * Create directories and files for all valid threshold banks.
 *
 * This is invoked from the CPU hotplug callback which was installed in
 * mcheck_init_device(). The invocation happens in context of the hotplug
 * thread running on @cpu.  The callback is invoked on all CPUs which are
 * online when the callback is installed or during a real hotplug event.
 */
void mce_threshold_create_device(unsigned int cpu)
{
        unsigned int numbanks, bank;
        struct threshold_bank **bp;

        if (!mce_flags.amd_threshold)
                return;

        bp = this_cpu_read(threshold_banks);
        if (bp)
                return;

        numbanks = this_cpu_read(mce_num_banks);
        bp = kzalloc_objs(*bp, numbanks);
        if (!bp)
                return;

        for (bank = 0; bank < numbanks; ++bank) {
                if (!(this_cpu_read(bank_map) & BIT_ULL(bank)))
                        continue;
                if (threshold_create_bank(bp, cpu, bank)) {
                        __threshold_remove_device(bp);
                        return;
                }
        }
        this_cpu_write(threshold_banks, bp);

        if (thresholding_irq_en)
                mce_threshold_vector = amd_threshold_interrupt;
        return;
}